Re: [PATCH 5/7] rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s

Miguel Ojeda
2025-05-04T18:15:34Z

On Sun, May 4, 2025 at 7:30 PM Tamir Duberstein <tamird@gmail.com> wrote:
>
> Alice pointed this out in another thread but: one of the downsides of
> returning Result is that in the event of failure the line number where
> the error occurred is no longer contained in the test output. I'm 👎
> on this change for that reason.

We could perhaps customize `?` to help here, e.g. printing a trace or
panic, with the `Try` trait or similar.

Related to this: I thought about saying in the guidelines that `?` in
tests is intended for things that you would normally use `?` in
similar kernel code, i.e. things that the test is not "testing",
rather than things that you would want to assert explicitly. Thus the
actual code under test should still have `assert!`s in the right
places. I did that in the sample. That way, having `?` would still
simplify a lot of test code and yet allow us to differentiate between
code under test vs. other code failing.

> These changes don't depend on returning `Result` from the tests
> AFAICT. Can they be in a separate patch?

Not sure what you mean. The change below uses `?`, which is what
allows this to be removed.

Thanks!

Cheers,
Miguel